42 THE OCEAN. 



air, and contracts with a force remaikable when we 

 consider its extreme thinness. If the paper be thin, 

 its four corners will in a moment be brous^ht almost 

 in contact with each other." The best method of ob- 

 viating this inconvenience is said to be, when we 

 suppose it is almost dry, to liave a flat book held 

 open, and the pressure being taken off, to remove the 

 specimen along with the drying-paper covering it, 

 as quickly as possible into the book, which must be 

 instantly shut, and not opened till the next day, or 

 till we know that it is thoroughly dry.* 



There is a substance which has been lately intro- 

 duced as an article of commerce, intended as a substi- 

 tute for Iceland moss, and sold by the London 

 druggists by the name of Carrageen moss ; notwith- 

 standing its name, however, it is a true Alga, Chon- 

 drus crispus. It is an exceedingly variable species, 

 but its most usual form is that of a flat leaf, spreading 

 somewhat triangularly, or rather so as to give to its 

 outline the figure of one-fourth of a circle : the edge 

 is branched into numerous flat segments overlapping 

 one another. When viewed under water, in a grow- 

 ing state, it gives out beautiful prismatic hues, the 

 tips of all the segments appearing of the most bril- 

 liant azure hue. Containing a large quantity of 

 gelatine, it has been successfully applied, instead of 

 isinglass, in the making of blanc-mange and jellies. 

 A fucus, probably allied to tliis, found at the Cape of 

 Good Hope, is boiled into a jelly, and, being mixed 

 with sugar and the juice of lemons or oranges, makes 

 a very agreeable dish. 



* Drummoud. 



